O. Ashayerizadeh, B. Dastar , M. Shams Shargh, M. Khomeiri,
Volume 12, Issue 43 (4-2008)
Abstract
This experiment was conducted to determine the performance and intestinal microflora population of broiler chicks in diets supplemented with Roxarsone, Avilamycin and Formycin gold during starter period. A basal diet was formulated according to NRC (1994) recommendation for starter (0-21 d) period and also supplemented with appropriate amounts of the mentioned growth promoters. Each of the treatment was fed to 5 replicates of 18 Ross 308 male broilers. The birds were raised on pen floor for 21 days. The microflora population in crop and ileum parts was measured on appropriate bacteriological media. Results of experiment indicated that supplementation of Roxarsone and Avilamycin, especially their combination to broiler diets, significantly improved body weigh gain of birds (P<0.05). Feed consumption and feed conversion ratios were not affected by any of the mentioned growth promoters. Adding all the growth promoters to the basal diet, except for the treatment of 0.05 percent Formycin gold, decreased total bacterial numbers in crop and ileum parts. Broilers fed diets containing Roxarsone plus Avilamycin had the lowest total bacterial population and were significantly different from those fed the basal diet (P<0.05). Supplementing broiler diets with all the growth promoters increased lactic acid bacteria population in crop, and decreased coliforms population in ileum parts. Lactic acid bacteria population was the highest in broilers fed Roxarsone plus Avilamycin and coliforms population was the lowest in birds fed 0.2 percent Formycin gold, being significantly different from basal diet (P<0.05).
Z Taraz, B Dastar,
Volume 13, Issue 48 (7-2009)
Abstract
This experiment was conducted to compare the effects of Roxarsone (Rox) and Bacitracin methylen disalicylat (BMD) on the performance of broiler chicks. A control corn-soybean meal diet without growth promoter was formulated according to NRC (1994) recommendation for starter (0-21d) and grower (22-42d) periods. The control diet was also supplemented with Rox (50 mg/kg diet ) BMD (55 mg/kg diet) as well as the combination of Rox (50 mg/kg diet ) and BMD (55 mg/kg diet) in order to prepare 4 dietary treatments. Five replicate groups of 15 Ross 308 broiler chicks were assigned to each dietary treatment. Data was analyzed in a completely randomized design. Results of experiment indicated that individual supplementing of diet with Rox as well as BMD led to improved body weight gain and feed conversion ratio compared to the basal diet. However, those birds fed diet containing the combination of these two compounds had significantly higher body weight gain and lower feed conversion than other groups ( P<0.05 ). Neither Rox nor BMD had any significant effect on feed intake. Birds fed diets supplemented with Rox or BMD had better carcass composition than those fed Basal diet. Based on the present results, supplementing broilers diets with Rox leads to improved body weight gain and feed conversion ratio in broilers. However, supplementing broiler diets with combination of Rox and BMD has a more positive effect on the performance and carcass composition in broiler chicks.
